Output Feedback Controller Design Research Articles

Design of Robust PID Controller using Static Output Feedback framework

This paper considers the design of a robust PID controller for higher order MIMO plants. The design problem is first recast into a Static Output Feedback (SOF) controller design problem and then the transformed SOF problem is solved within the framework of Linear Matrix Inequalities (LMIs) through a decomposition of the Lyapunov matrix variable. Sufficient LMI criteria are derived that ensure H∞ performance of the underlying system. By means of a numerical example, it is shown that the designed controller yields less conservative results. Also, a comparative study is done with the existing techniques to demonstrate the efficacy of the proposed method.

Efficient Non-Conservative Realization of Dynamic Scaling-Based Output-Feedback Controllers via a Matrix Pencil Approach

A general matrix pencil based approach is developed for efficient non-conservative realization of dual dynamic high-gain scaling based control designs. A general class of uncertain feedforward-like nonlinear systems is considered and it is shown that the output-feedback control design procedure can be cast into a set of matrix pencil based sub-problems that capture the detailed system structure, state dependence structure of uncertain terms, and the precise roles of the design freedoms in the context of the detailed structure of the Lyapunov inequalities. The design freedoms in the dynamic high-gain scaling based design are extracted in terms of generalized eigenvalues of the formulated matrix pencil structures. It is seen that the proposed matrix pencil based approach greatly reduces design conservatism and algebraic complexity compared to prior results on dynamic high-gain scaling based control designs.

Finite-time fuzzy output-feedback control for $ p $-norm stochastic nonlinear systems with output constraints

<abstract> <p>This paper investigates the finite-time control problem of $ p $-norm stochastic nonlinear systems subject to output constraint. Combining a tan-type barrier Lyapunov function (BLF) with the adding a power integrator technique, a fuzzy state-feedback controller is constructed. Then, an output-feedback controller design scheme is developed by the constructed state-feedback controller and a reduce-order observer. Finally, both the rigorous analysis and the simulation results demonstrate that the designed output-feedback controller not only guarantees that the output constraint is not violated, but also ensures that the system is semi-global finite-time stable in probability (SGFSP).</p> </abstract>

Adaptive Neural Output-Feedback Controller Design of Switched Nonlower Triangular Nonlinear Systems With Time Delays.

In this article, we study the issue of adaptive neural output-feedback controller design for a class of uncertain switched time-delay nonlinear systems with nonlower triangular structure. The prominent contribution of this article is that the delay-dependent stability criterion of nonswitched nonlinear systems is successfully extended to that of switched nonlower triangular nonlinear systems. The design algorithm is listed as follows. First, a switched state observer is designed such that the error dynamic system can be generated. Second, neural networks, adaptive backstepping technique, and variable separation method are, respectively, applied to construct a common controller for all subsystems, in which the Lyapunov-Krasovskii functionals are deliberately constructed such that the average dwell-time scheme can be employed to guarantee the stability and performance of the closed-loop system, despite the existence of time delays. Third, the stability analysis process confirms in detail that all the variables of the closed-loop system are semiglobally uniformly ultimately bounded. Finally, simulation study is given to show the validity of the proposed control approach.

Solution to negative-imaginary control problem for uncertain LTI systems with multi-objective performance

This paper addresses the problem of dynamic output feedback controller synthesis in LMI framework for LTI generalized plants with negative-imaginary uncertainties. The proposed technique transforms the controller synthesized nominal closed-loop system into a strongly strict negative-imaginary system and exploits the DC loop gain condition pertaining to negative-imaginary theory to establish internal stability in presence of negative-imaginary uncertainties. Apart from making the closed-loop system robustly stable, the designed output feedback controller also facilitates multi-objective performance of the closed-loop system such as minimizing the H2 and H∞ norms, reducing the peak overshoot, increasing the decay rate, optimizing the settling time, etc. Illustrative examples have been studied to demonstrate the usefulness of the proposed control scheme. A thorough μ-analysis subjected to ‘mixed’ two-block perturbations is included in the examples to show that the designed controller can also facilitate a certain level of robust H∞ performance in presence of stable NI/SNI uncertainties.

Stabilization for a chain of saturating integrators arising in the visual landing of aircraft with sampling

We provide a new output feedback control design for a chain of saturating integrators with imprecise output measurements where the outputs can also contain delays and sampling. Using a backstepping approach that leads to pointwise delays in the control and a dynamic extension, we prove input-to-state stability using a new dynamic extension approach. We utilize our main result to solve a problem in the visual landing of aircraft in the glide phase in the presence of delayed and sampled image processing.

Finite-region dissipative dynamic output feedback control for 2-D FM systems with missing measurements

This paper focuses on the finite-region dissipative dynamic output feedback control problem for a class of discrete-time two-dimensional (2-D) Fornasini–Marchesini (FM) systems with missing measurements. Firstly, the definitions of finite-region boundedness (FRB) and finite-region (T, S, R)-ϑ-dissipativity are introduced for 2-D FM systems. Secondly, sufficient conditions on the FRB and finite-region (T, S, R)-ϑ-dissipativity of the resultant closed-loop 2-D systems are obtained by the construction of the Lyapunov function and the special recursive formulas. Thirdly, based on the decoupling technique, the desired dynamic output feedback controller design method for the considered 2-D systems is further provided. In the end, an example of the metal rolling process is given to show the effectiveness of the proposed design results.

Output‐based resilient event‐triggered control for networked control systems under denial of service attacks

This study is concerned with the output-based resilient event-triggered control for networked control systems (NCSs) subject to denial of service (DoS) attacks, where 'resilient' is interpreted as that the NCSs can tolerate a larger time delay with a certain degree of performance degradation when there are DoS attacks. Otherwise, the NCSs run with $H-{\infty }$H∞ performance. In order to characterise DoS attacks, an additional positive term which implies the effects of DoS attacks is imposed on the pre-designed triggering condition. By considering the fact that only partial output measurements can be obtained, the output-based security performance analysis as well as an output feedback controller design under the proposed event-triggered strategy is conducted with Lyapunov-Krasovskii method and linear matrix inequalities technique. At last, the simulation results show that the designed controller is resilient to DoS attacks with less dependent on the transmission packets while sacrificing some control performance.

Modulating function‐based fast convergent observer and output feedback control for a class of non‐linear systems

In this study, a new observer for a class of non-linear single input/single output systems is proposed. This observer is based on a modulating function with time/output dependent coordinates transformation which transforms the original system into a like-type observer canonical form. In the new coordinates, the initial conditions are annihilated. This property permits to construct a fast convergent deadbeat observer activated after an time delay chosen in order to avoid the singularity of the transformation at the initial time t = t 0 . The finite-time convergence of the observer is established, i.e. it is shown that the estimation error is bounded in finite time. The proposed observer is used in an output feedback controller design. Using the already established results on the output feedback stabilisation of non-linear input-affine systems, the separation principle is addressed here and the authors show that output feedback controller guarantees under certain conditions the stability of the closed-loop system. Two numerical examples are given to illustrate the effectiveness of the proposed observer-based output feedback controller.

Design of a fault-tolerant output-feedback controller for thickness control in cold rolling mills

This work devotes to designing the fault-tolerant output feedback controller for the hydraulic automation gauge control system of cold rolling mills. The mathematical model of the rolling mill is constructed, in which the possible actuator failures are considered randomly occurring and obey semi-Markov process. By constructing a desired controller based on the measured output, the stabilization and the dissipativity of the considered system are realized. Data from actual equipment are provided to test the practicability of the method.

Dynamic output feedback control of discrete-time switched GRNs with time-varying delays

This paper focuses on the dynamic output feedback (DOF) controller design problem for discrete-time switched genetic regulatory networks (GRNs) with time-varying delays. Firstly, based on the average dwell time method and piecewise Lyapunov–Krasovskii functional, the exponential stability criteria are derived by utilizing a new summation inequality, an extended reciprocally convex matrix inequality and the extension of the property of quadratic convex function. Then, sufficient conditions for a desired DOF controller are obtained such that the resulting closed-loop system is exponentially stable. Moreover, the explicit expressions of all desired controllers are given. Finally, numerical example is provided to verify the effectiveness of the proposed design techniques.

Robust dissipative observer‐based control design for discrete‐time switched systems with time‐varying delay

This study deals with (Q,S,R)-γ-dissipative output feedback control design for a class of switched systems with time-varying delay and unmeasurable states. The purpose is to design an observer-based controller and a switching rule to ensure both exponential stability and strict dissipativity of the resulting closed-loop switched systems. Using an augmented switched Lyapunov-Krasovskii functional with triple sum and the improved reciprocally convex combination approach, new sufficient conditions are developed in terms of linear matrix inequalities. Simulation examples are included to demonstrate the validity and effectiveness of the proposed design technique.

Observer-based decentralized control of large-scale stochastic high-order feedforward systems with multi time delays

This paper investigates the problem of observer-based decentralized control for a class of large-scale stochastic high-order feedforward systems with multi time delays. By using the homogeneous domination idea and constructing the implementable observer, the decentralized output-feedback controller design scheme is firstly proposed. Then, with the aid of stochastic time delay system stability theory, the globally asymptotically stable in probability of the closed-loop system is verified by selecting an appropriate Lyapunov–Krasoviskii functional. Finally, an example is provided to demonstrate the efficiency of the proposed design method.

Adaptive Fuzzy Tracking Control Design for a Class of Uncertain Nonstrict-Feedback Fractional-Order Nonlinear SISO Systems.

In this article, a class of uncertain nonstrict-feedback fractional-order nonlinear single-input-single-output (SISO) systems is investigated. Fuzzy-logic systems (FLSs) are employed to approximate the unknown nonlinear functions and model the uncertain fractional-order nonlinear systems. For the states measurable case, an adaptive fuzzy state-feedback control scheme is developed under the framework of the backstepping technique. For the states unmeasurable case, an observer-based output-feedback control design is proposed by introducing a serial-parallel estimation model and using the dynamic surface control (DSC) technique. Under the drive of the reference signals, the semiglobally uniformly ultimate boundedness for all signals and the tracking errors converging to a small neighborhood of the origin are proved based on the Lyapunov function theory by choosing appropriate design parameters. Two examples with numerical simulations are presented to illustrate the availability of the proposed control approaches.

New LMI conditions for H ∞/H 2 output feedback control of linear discrete-time systems

ABSTRACT This paper addresses the design of static output feedback controller for linear discrete-time systems. New sufficient criteria are derived for designing and controllers. The corresponding design criteria are presented in the form of Linear Matrix Inequalities (LMIs). The development involves certain relaxations of the LMI variables through appropriate use of bounding inequalities leading to less conservative LMI design criteria. The proposed method is compared with existing ones through numerical examples to illustrate the effectiveness of the design method.

Finite-Time ${\mathscr{H}_{\infty}}$ Asynchronous Control for Nonlinear Markov Jump Distributed Parameter Systems via Quantized Fuzzy Output-Feedback Approach

This article focuses on the asynchronous output-feedback control design for a class of nonlinear Markov jump distributed parameter systems based on a hidden Markov model. Initially, the considered systems are represented by a Takagi-Sugeno fuzzy model via a sector nonlinearity approach. Furthermore, asynchronous quantizers are introduced to save the limited communication resource in engineering applications. Then, based on the Lyapunov direct method and some inequality techniques, a series of novel stability criteria, which guarantee the finite-time boundedness and [Formula: see text] disturbance attenuation performance of the target plants, is established in the form of spatial differential linear matrix inequalities. Finally, a simulation study is provided to verify the viability of the developed approach.

ℋ2 static output feedback switching function design based on a time-varying Lyapunov function approach

This paper treats the control design of an output-dependent switching function for discrete-time switched linear systems, without considering the synthesis of any additional dynamic structure. The conditions are based on a convex, but time-varying, Lyapunov function and are expressed in terms of Linear Matrix Inequalities (LMIs). The state feedback switching function design can be obtained as a particular case and is simpler to handle from theoretical and numerical viewpoints compared to other methods available in the literature, as for instance, those based on Lyapunov–Metzler inequalities. The novelty of the proposed control methodology is the adoption of a time-varying Lyapunov function, which together with the presence of a key matrix, allow us to treat the static output feedback control design, taking into account a guaranteed performance cost. Academic examples are used for comparison and illustration. The proposed control technique is experimentally validated in an active suspension system representing a quarter-vehicle.

Design of output feedback controller for stochastic feedforward systems with unknown measurement sensitivity

This paper investigates the problem of output feedback control for a class of stochastic feedforward systems with unknown measurement sensitivity. Unknown measurement sensitivity is only a bounded continuous function and its derivative is not guaranteed. To solve the considered problem, the low-gain linear K-filters are performed without using the information of the output, and a gain design method based on backstepping is proposed to construct an output feedback controller. By the stochastic stability theory, the asymptotically stable in probability of the closed-loop control system is analyzed. A nonlinear liquid level control resonant circuit system with unknown measurement sensitivity is given to demonstrate the effectiveness of the proposed control scheme.

Multiobjective Fault-Tolerant Control for Fuzzy Switched Systems With Persistent Dwell Time and Its Application in Electric Circuits

This article concentrates on the output feedback controller design problem for discrete-time nonlinear switched systems with actuator faults. The Takagi–Sugeno fuzzy model is adopted to approximate the nonlinearity of the plant with a set of local linear models. The persistent dwell-time (DT) switching law, which is more general than DT or average DT switching, is introduced to govern the switching among subsystems. In order to alleviate the effects of actuator failures on system stability and performance, a synthesized fault-tolerant output feedback controller ensuring various performance requirements is designed. Intensive attention is focused on establishing sufficient conditions, which can guarantee the exponential mean-square stability as well as the prescribed extended dissipativity property of the closed-loop system. By virtue of the Lyapunov stability theory and appropriate matrix transformation methods, the desired controller gains can be obtained by solving a convex optimization problem. The developed method is finally applied to address the control issue of a tunnel diode circuit system model to illustrate its efficiency and applicability.

Output Feedback Stabilization for MIMO Semi-linear Stochastic Systems with Transient Optimisation

This paper investigates the stabilisation problem and consider transient optimisation for a class of the multi-input-multi-output (MIMO) semi-linear stochastic systems. A control algorithm is presented via an m-block backstepping controller design where the closed-loop system has been stabilized in a probabilistic sense and the transient performance is optimisable by optimised by searching the design parameters under the given criterion. In particular, the transient randomness and the probabilistic decoupling will be investigated as case studies. Note that the presented control algorithm can be potentially extended as a framework based on the various performance criteria. To evaluate the effectiveness of this proposed control framework, a numerical example is given with simulation results. In summary, the key contributions of this paper are stated as follows: 1) one block backstepping-based output feedback control design is developed to stabilize the dynamic MIMO semi-linear stochastic systems using a linear estimator; 2) the randomness and probabilistic couplings of the system outputs have been minimized based on the optimisation of the design parameters of the controller; 3) a control framework with transient performance enhancement of multi-variable semi-linear stochastic systems has been discussed.